Guard against single operand multiplication when detecting like terms This *shouldn't* happen, but it apparently does in some pathological cases so guard against a single operand multiplication to prevent a crash.

\.exe$
\.o$
\.d$
\.a$
~$
\.orig$
/lwbasic$
/lwlink$
/lwobjdump$
/lwar$
/lwasm$
/lwcc/lwcc$
/lwcc/lwcc-cpp$
/lwcc/lwcc-cc

# for windows
\\.suo$
\\.sdf$
\\.opensdf$
\\Debug$
\\Release$